Process for controlling the growth and reproduction of microorganisms



United States Patent 3,164,552 PRES FUR CQN'ERGLLING THE GE'RQWTH AND REPRODUCTEQN @F MHRGGRGANESM Leonard L. Wolfson, Tinicy Park, ill, assignor to Nalco Chemical Company, a corporation of Delaware No Drawing. Filed Dec. 24, 1953, Ser. No. 782,635 18 Claims. (Cl. 252--8.55)

This invention is concerned with new and improved microbiocidal agents and their use in the control of microorganisms commonly found in industrial process waters. More particularly, it is related to a new class of bactericides which are eifective in the control of sulfate reducing bacteria under aqueous conditions where high concentrations of dissolved inorganic salts are prevalent.

One of the most difficult problems encountered in the use of known microbiocides in the treatment of the various types of industrial process waters is that the agents now available tend to be relatively specific as to the various species of microorganisms upon which they operate. Thus, while a microbiocide might be extremely effective in controlling fungi such as Aspergillus niger, it would not necessarily be eflective in controlling an anaerobic species of bacteria.

One of the most difiicult species of bacteria to control are the well known sulfate reducing bacteria, when their environment is composed of water containing relatively large amounts of dissolved inorganic salts. Under these environmental conditions, very few microbiocides will show any inhibition of sulfate reducing bacteria regardless of the dosage at which they are employed. Also, the few compounds found to be effective often require relatively large dosages in order to give satisfactory results, thereby increasing the cost of treating large quantities of water. It is known that most of the microbiocides are toxic to humans and animals in high concentrations, and for this reason it is considered important to avoid the use of highly toxic compounds in any concentration and to use the less toxic compounds in as low concentrations as possible. See, for example, the discussion by R. C. Allred, The Role of Microorganisms, Producers Monthly, vol. 18, No. 4, page 18.

The most difiicult industrial problem associated with sulfate reducing bacteria is in high brines which are frequently encountered in the process known as water floodmg.

When an oil well ceases to flow by the natural pressure in the formation and/or substantial quantities of oil can no longer be obtained by the usual pumping methods, various processes are sometimes used for the treatment of the oil-bearing formation in order to increase the flow of oil. These processes are usually described as secondary recovery processes. One such process which is used quite frequently is the water flooding process wherein water is pumped under pressure into what is called an injection well and oil, along with quantities of water, that have been displaced from the formation, are pumped out of an adjacent well usually referred to as a producing well. The oil which is pumped from the producing well is then separated from the water that has been pumped from the producing well and the water is pumped to a storage reservoir from which it can again be pumped into the injection well. Supplementary water from other sources may also be used in conjunction with the produced water. When the storage reservoir is open to the atmosphere and the oil is subject to aeration, this type of water flood ing system is referred to herein as an open water flooding system. If the water is recirculated in closed system without substantial aeration, the secondary recovery method is referred to herein as a closed flooding system.

The water which is introduced into the injection wells may vary considerably in composition from one field to another. Frequently it contains relatively large quantities of dissolved salts such as sodium chloride and therefore can be described as a brine. It may also contain other salts such as those of calcium, magnesium, barium and strontium. Some iron salts may likewise be present. In some cases these salts are [added to a fresh water to prevent clay minerals from swelling and sealing otf porous oil sands, but in most instances their occurrence is natural.

It would be a valuable contribution to the art if a class of microbacterial agents were available which were effective in the control of sulfate reducing bacteria particularly in processes using waters containing substantial quantities of inorganic salts. Also beneficial would be a group of bactericides which would act to effectively control a wide variety of microorganisms, including the sulfate reducing bacteria, at a low economical dosage.

It, therefore, becomes an object of the invention to provide a new process for controlling the growth of microorganisms with microbiocides which are effective in the control of sulfate reducing bacteria when such are found in the presence of waters containing relatively large amounts of dissolved inorganic salts.

Another object is to provide such control of sulfate reducing bacteria by the use of amicrobiocide at low dosage in a liquid medium. Such object includes conrolling the growth of a large variety of microorganisms in addition to the sulfate reducing bacteria.

An additional object is to provide new and useful water flooding processes. 1

A further object is to provide improved aqueous liquids useful as injection fluids in the secondary recovery of petroleum by water flooding. Other objects will appear hereinafter.

In accordance with the invention, it has been found that sulfate reducing bacteria in a liquid aqueous medium containing dissolved inorganic salts may be effectively controlled in their growth and reproduction cycles by treating such bacteria with a biologically active amount of a halogen substituted nitropar-afiin which contains from two to not more than six carbon atoms in chain length. This class of microbiocidal agents is also effective in controlling a large variety of other species of bacteria, fungi and algae of the types most commonly found in industrial process waters. They are effective against most strains of bacteria, including the sulfate reducing bacteria, at dosages ranging from 0.5 part per million to parts per million with excellent results generally being obtained at dosages no larger than between 5-25 parts per million.

While halogen substituted nitroparaflins falling within the above defined limits are considered as being useful in the practices of the invention, a specific and extremely valuable group of these compounds are those halogen substituted nitroparaflins having a general structural formulae designated below:

In the above formulae, R and R will be either hydrogen or a lower acyclic hydrocarbon group. Since the compounds of the invention should not contain more than 6 carbon atoms, the sum of R and R should not exceed 4 carbon atoms in chain length. Hal in the above formulae represents fluorine, chlorine, bromine or iodine.

It is apparent from the structure shown above that the preferred compounds of the invention have the halogen and nitrogen substituents on the same carbon atom. When more than one halogen atom is contained in the compound, it is preferred that the halide-s be gem dihalides (i.e., the halogen atoms are attached to the same carbon atom). The preferred compounds should also contain not more than 2 halogen atoms. Although, for purposes of the invention, more than two halogen atoms may be present, no particular advantage is obtained when such multiple halogen substituents are contained in the nitropanaffin molecule.

Examples of specific halogen substituted nitroparafiins that may be used as microbiocidal agents are listed below in Table I.

TABLE I Composition No.: Halogen substituted nitroparaffin I l-chlorol -nitropro pane. II l-chloro- 1 -nitroethane. III 1 -bromo- 1 -nitrohexane.

IV l-iodo- 1 -nitroethane.

V 2-chloro-2-nitroethane. VI 1, l-dichloro- 1 -nitropropane. VII 3-bromol anitropentane. VIII l-fluoro-l-nitroethane.

Of the compounds shown above, the most useful are l-chloro-l-n-itropropane, l,l-dichloro-l-n-itropropane, lchloro-l-nitroethane and Z-chloro-Z-nitropane.

The two to six carbon atom halogen-containing nitroparafiins are relatively non-volatile and can be handled and used at concentrations according to the invention without toxic efiects upon humans, domestic animals and the like. By comparison, halogen substituted nitromethanes are unsatisfactory for use in treating any industrial process waters for the control of microorganisms due to the toxicity problems associated with the use of these materials. For example, trichloronitromethane, more commonly known as ohloropicrin, is a well known systemic poison and is exteremly dangerous to handle.

Nearly all the compounds of the invention are soluble in water at use concentrations. When more concentrated solutions are desired, it is necessary to first prepare a concentrated solution of the halogen substituted paraffin in a low molecular weight inert organic solvent such as isopropanol, acetone, dimethylform-amide and the like. When it is desired to dilute concentrated formulae with water, it is preferable first to add to the halogen substituted nitroparaffin a high molecular weight amino compound as a carrier, preferably a higher monoalkyl substituted primary amine salt (e.g., lauryl amine, oleyl amine, Duomeen C, or the like, in the form of the acetate salts) or a higher mono-alkyl substituted imidazoline of the type shown below in the form of a salt, e.g., the acetate, which is preferably formed in situ:

I H (CHgC IIZN) DH where R is a higher alkyl group containing from 5-21 atoms in chain length and n is a small whole number not greater than 3, e.g., compound C where R is heptadecenyl, or the hydrocarbon radical from tall oil; or compound D where R is heptadecenyl or the hydrocarbon radical of tall oil, and n is l or 2.

The amounts of higher alkyl substituted amine or imidazoline required to form water soluble complexes with halogen substituted nitroparafiins are firom 1.5 to 2 moles of organic nitrogen base to one mole of halogen substituted nitroparafiin. In the case of substituted imidazolines where there are one or more basic nitrogen atoms attached to the heterocyclic ring in the 1-position, each basic nitrogen atom may be considered as an individual mole of product for the purpose of forming these com plexes. When the basic portion of the imidazoline is in the ring, only one of the nitrogen atoms is reactive.

To aid in maintaining the stability of formulae containing halogen substituted nitroparaflins and higher alkyl substituted primary amines or imid-azolines, it is often desirable to add minor amounts of mineral acids, or lower molecular weight organic carboxylic acids such as acetic acid. The amount of acid necessary depends on the particular solvent and components of the formula. The quantity of acid generally will never exceed 10% by weight of the total formulation.

The higher alkyl substituted amines or imidazolines, while aiding in the preparation of the water base formula, have the added advantage of rendering such formulation relatively non-corrosive where the corrosivity of formulations is important. Many corrosion-inhibiting and film-forming high molecular weight amines and imidazolines are known in the art and are valuable additives in compositions containing the biologically active agents of the present invention. In general, these corrosioninhibiting compounds are characterized by at least one basic nitrogen atom in a hydrocarbon structure containing from about 12 up to as high as 72 carbon atoms. It is sometimes beneficial to add additional corrosion inhibitors such as, for instance, polyphospha-tes, alkali metal nitrites, alkali metal nitrates, alkali metal borates and alkali metal chromates, to insure that the products will be noncorrosive to both ferrous and nonierrous metals. It is also beneficial to add other biologically active agents to those of the present invention for specific formulations. The halogenated ni-troparalfins having 2 to 6 carbon atoms retain their effectiveness under a wide variety of conditions and are compatible with most additives which one would expect to find in the aqueous compositions of water flooding processess.

The invention is further illustrated by the following examples.

Example I In order to determine the microbiocidal efficiency of the halogen substituted nitroparaffins the following two test methods were employed.

TEST METHOD A.SCREENING INHIBITION TEST Culture media:

Sodium lactate (60%) "ml--- 4.0 Yeast extract gm 1.0 Ascorbic acid gm 0.1 MgSO 7H O gm 0.2 K HPO (anhydrous) gm 0.01 Fe(SO (NH 6H O gm 0.1 NaCl gm 10.0 Deionized water ml 1000.0

The ingredients were dissolved by stirring, and the pH was adjusted to 7 .27.5 with 6 N NaOH. The media was then auto-slaved at 15 1b./15 minutes and was ready for use in the test. a

The organisms were a culture of sulfate reducers (Desulfovibrio) that were obtained from the American Petroleum Institute and were designated as APE-A culture. The inocula for the tests were from the third successive 24 hour transfer, and showed blackening after each 24 hour transfer.

Stock solutions of the bacteriostat to be screened were prepared as 0.9% solutions by weight in ethanol. On the day of the test, 0.09% solutions by volume were prepared in deionized water from the stock solutions and s v were the working solutions for the tests.

To sterile 18 ml. screw capped test tubes sufficient amounts of the chemicals being tested were added to give the desired concentration of bacteriostat in 18 ml. After addition of the chemical, the room temperature media, to which had been added ml. of culture per liter, was poured carefully into the screw cap tubes to completely fill them, care being taken that no liquid was allowed to overflow from the tubes. Duplicate tubes were prepared in every dilution in addition to a control tube which contains no chemical. The tubes were tightly capped so that no air was entrapped.

The tubes were incubated at 37 C. for 7 days and then observed for results. Growth'of the sulfate reducers was evinced by intense blackening of the tubes, while inhibition of growth showed no change in appearance.

Using the above described test methods, results were obtained:

From the above table, it is observable that the halogen substituted nitroparafiins of the invention usually have the same inhibition range in controlling sulfate reducing bacteria regardless of whether the brine concentration is dilute or concentrated. This fact is believed to be sig- The desired concentrations of chemicals were obtained in the 18 ml. tubes by adding the following amounts from the 0.09% solution.

Concentration (p.p.m.) Amount of solution 100 ml 2.0 50 ml 1.0 40 ..mL.. 0.8 mml 0.6 20 ml 0.4 10 cml 0.2

5 ml 0.1 1 ml 0.0

TEST METHOD B In this method, known as the gas tube method, the

subculture medium consisted of 24 grams of dextrose, 1

the tubes a given amount of chemicalto be tested was introduced using an appropriate concentration of stock chemical to avoid more than a 5% error in final dilution. For this purpose the volume of chemical introduced should be 1 ml. or less. The chemical and: inoculated medium were mixed gently.

A control test was also run inwhich the chemical was omitted and 1 ml. of water substituted. In mixing, each tube was inverted in such a manner as to fill the upright closed end of the tube with test liquid; The tubes. were incubated at 30 C. for 24 hours. At the end of one hour contact and again after 24 hours contact, a loopful of the test mixture with withdrawn from each tube and inoculated in a subculture tube containing 10 ml. of sterile nutrient broth. The subculture tubes were incubated at 37 C. for 48 hours and examined for growth. The results of these tests recorded in parts per million (p.p.m.) indicated one and 24 hour killing ranges. gas production for inhibition level was recorded at 48 hours.

The i solubility of inorganic salts. The expression fmicroornificant since it is well known that most bactericidal agents are relatively ineffective in the presence'of concentrated brines.

For purposes of comparison it will be seen from Table II that the nitroparafiins and the chlorinated paraifins are not comparable to the halogen substituted nitroparaffins in their activity against sulfate reducing bacteria. The l-chloro-l-nitropropane' provides exceptionally good results at a very low dosage.

Example 11 The following composition illustrates a concentrate prepared for the practice of the invention.

Ingredients: Percent by weight Imidazoline of Formula D where n is land R is the hydrocarbon radical fromtall oil contain- 1 ing 70% to by weight of fatty acids and having a molecular weight within the range of 340 to 364 41.2 Acetic acid 8.8

Isopropanol 15.0

f l-chloro-l-nitropropane 10.0 Water 25.0

, Example 111 g The following composition illustrates another concen- In the compositions described in Examples 'II and III the high molecular weight amino compounds serve as carriers and are normally present in proportionsof about 1.5 to 5 times the weight of the biologically active halogen substituted nitroparaffin. These high molecular weight amino compounds also act as corrosion inhibitors.

. For purposes of clearly defining the scope of the inven- 7 tion, when reference is made to dilute and concentrated brines, it is meant to be inferred that concentrated brines include those solutions containing at least 3% by'w'eight of dissolved inorganic salts and encompasses those solutrons of inorganic salts which contain the saturation ganisms includes such biological genera asbacteria,

tended to include both the primary the following In addition to being treated agents for water-flooding operations, the compositions are excellent treating agents for the control of microorganisms found in salt water disposal wells.

This application is a continuation-in-part of copcnding application, Serial No. 717,807, filed February 27, 1958, now abandoned.

The invention is hereby claimed as follows:

1. The method of controlling the growth of sulfate reducing bacteria in a liquid aqueous medium containing dissolved inorganic salts which comprises treating said bacteria in such medium with a biologically active amount of a halogen substituted nitroparafiin containing from 2 to not more than 6 carbon atoms in chain length.

2. The method of controlling the growth of sulfate reducing bacteria in concentrated brines containing such bacteria which comprises treating said brines with a biologically active amount of halogen substituted nitroparaffin having the structural formula from the group consisting of:

where R and R are from the group consisting of hydrogen and lower acyclic hydrocarbon groups with the proviso that the sum of R and R is not greater than 4 carbon atoms, and Hal represents halogen.

3. The method of claim 2 where the halogen substituted nitroparaflin is l-chloro-l-nitropropane.

4. The method of claim 2 where the halogen substituted nitroparaflin is 1,l-dichloro-l-nitropropanc.

5. The method of claim 2 where the halogen substituted nitroparafi'ln is l-chloro-l-nitroethane.

6. The method of claim 2 where the halogen substituted nitroparaffin is 2-chloro-2-nitropropane.

7. In a flooding process for the recovery of oil from oil-bearing subterranean formations, the improvement which comprises flooding the oil-bearing subterranean formation with an aqueous liquid containing in excess of about 25 parts per million of a halogen substituted nitroparaffin having the structural formula from the group consisting of:

where R and R are from the group consisting of hydrogen and lower acyclic hydrocarbon groups with the proviso that the sum of R and R is not greater than 4 carbon atoms, and Hal represents halogen.

8. In a process of secondary oil recovery characterized by the step of injecting flooding water into oil-bearing subterranean formations to displace portions of the residual oil therein, the improvement comprising having present in said injected flooding water in excess of about 3-10 ppm. of a dichlornitroalkane having the following formula:

01 CI-I -(J-NO; h

9. In a process of secondary oil recovery characterized by the step' of injecting flooding water into oil-bearing subterranean formations to displace portions of the residual oil therein, the improvement comprising having present in said injected flooding water in excess of about 3-10 ppm. of a dichloronitroalkane having the following formula:

and

where R and R are from the group consisting of hydrogen and lower acyclic hydrocarbon groups, with the proviso that the sum of R and R is not greater than 4 carbon atoms, and Hal represents halogen.

12. The aqueous liquid of claim 11 Where the halogen substituted nitroparaffin is l-chloro-l-nitropropane.

13. The aqueous liquid of claim 11 where the halogen substituted nitroparaffin is l,l-dichloro-l-nitropropane.

14. The aqueous liquid of claim 11 where the halogen substituted nitroparaflin is l-chloro-l-nitroethane.

15. The aqueous liquid of claim 11 where the halogen substituted nitroparaffin is 2-chloro- 2-nitropropane.

'16. The aqueous liquid of claim 11 which contains from at least 0.5 to about 25 parts per million of the halogen substituted nitroparafiin.

17. An aqueous liquid as claimed in claim 11 which contains a high molecular weight amino compound as a carrier for said nitroparafiin, said amino compound having at least one basic nitrogen atom in a hydrocarbon structure containing from about 5 to 72 carbon atoms, such that said amino compound provides from 1.5 to 2 moles of organic nitrogen base to 1 mole of halogen substituted nitroparafiin.

18. An aqueous liquid as claimed in claim 11 which contains a high molecular weight imidazoline as a carrier for said nitroparafiin, said imidazoline containing a hydrocarbon group having from 5 to 21 carbon atoms, such that said imidazoline provides from 1.5 to 2 moles of organic nitrogen base to 1 mole of halogen substituted nitroparaflin.

(References on following page) References Cited in the file of this patent UNITED STATES PATENTS Chapman July 22, 1924 Kampa et a1. Apr. 2, 1929 Kyrides June 24, 1941 Hass Apr. 28, 1942 Harnden Apr. 15, 1947 Stayner et a1 Oct. 19, 1954 10 Prusick et a1 Jan. 31, 1956 Rydell Mar. 13, 1956 Hardy Sept. 25, 1956 Hutchinson et a1 June 17, 1958 FOREIGN PATENTS Australia May 25,1939

Italy Mar. 19, 1947 

1. THE METHOD OF CONTROLLING THE GROWTH OF SULFATE REDUCING BACTERIA IN A LIQUID AQUEOUS MEDIUM CONTAINING DISSOLVED INORGANIC SALTS WHICH COMPRISES TREATING SAID BACTERIA IN SUCH MEDIUM WITH A BIOLOGICALLY ACTIVE AMOUNT OF A HALOGEN SUBSTITUTED NITROPARAFFIN CONTAINING FROM 2 TO NOT MORE THAN 6 CARBON ATOMS IN CHAIN LENGTH.
 7. IN A FLOODING PROCESS FOR THE RECOVERY OF OIL FROM OIL-BEARING SUBTERAANEAN FORMATIONS,THE IMPROVEMENT WHICH COMPRISES FLOODING THE OIL-BEARING SUBTERRANEAN FORMATION WITH AN AQUEOUS LIQUID CONTAINING IN EXCESS OF ABOUT 2-5 PARTS PER MILLION OF A HALOGENSUBSTITUTED NITROPARAFFIN HAVING THE STRUCTURAL FORMULA FROM THE GROUP CONSISTING OF: 